What does the P wave on an EKG represent?

The P wave on an EKG represents atrial depolarization. This phase of the cardiac cycle occurs when the sinoatrial (SA) node, the heart's natural pacemaker, initiates an electrical impulse. This impulse spreads through the atria, causing them to contract and push blood into the ventricles. The depolarization of the atrial muscle is what generates the P wave on the electrocardiogram.

Understanding the significance of the P wave is crucial for interpreting EKG readings, as it reflects normal atrial activity. Any abnormality in the P wave can indicate atrial enlargement or other cardiac conditions affecting atrial function. Therefore, recognizing that the P wave specifically corresponds to the electrical depolarization of the atria helps in diagnosing and assessing various heart conditions.